Death Coil is a beginning death knight spell that unleashes some of the death knight's Runic Power to damage any living target or heal a friendlyundead target. While not specifically mentioned, Death Coil can be used to heal a death knight under the effects of [Lichborne] (including yourself).

Use: Permanently teaches you this glyph.Your Death Coil spell is now usable on all allies. When cast on a non-undead ally, Death Coil shrouds them with a protective barrier that absorbs up to 1133 + 0.514 * AP * 1 damage.

Notes

Death Coil is technically the reverse spell of the Holy Light ability of the Paladin class. Wherein the Holy Light heals friendly living units and damages the undead, Death Coil works the opposite; it damages living enemies and heals the undead.

Death Coil only heals your friendly undead units. It does not work on enemy undead.